If an exciting new study out of the UK’s University of Bradford holds up to scrutiny in coming months, your next routine physical could include a far-seeing test for hundreds of types of cancers — and you might not even need to drop trow to get it. The study presents evidence that a simple, easily run blood test can accurately identify patients who have cancer, though importantly it does not reveal which cancer that might be. As a routine early warning system, or a quick and easy test for patients presenting suspicious symptoms, this could save millions of dollars and just as many lives.

White blood cells, otherwise known as lymphocytes, are the body’s primary defense cells — when you have a viral or bacterial infection, a physical trauma, or even an invading parasite, white blood cells are a big part of the body’s response. As such, when you have a cancerous mass in your body, white blood cells are also involved in fighting that, and while they’re obviously not up to fighting off cancer all on their own, they do seem to at least try. This study was prompted by the question: if lymphocytes are fighting cancers we don’t even know about, perhaps the lymphocytes are carrying evidence of that fight, and thus of the presence of the cancer.

These days most blood tests can be quick and, more importantly, cheap.

The test here is called a Lymphocyte Genome Sensitivity test (LGS test), and it basically quantifies how sensitive a cell’s genetic material is to damage. In this study, the team bathed the prepared blood samples of more than 200 patients in ultraviolet light, doing some statistically reliable amount of damage to each genome. Then, a simple gel experiment separated the genome fragments by size, allowing the researchers to see a sort of comet tail spread out behind the damaged DNA, a spectrum of randomly broken or kinked molecules. In an LGS test, more broken DNA (and thus larger, longer tail) means a higher sensitivity to damage by UV light. The central finding of this paper is that the white blood cells of people with cancerous tumors are stressed, and have reliably higher genome sensitivity than those of people who do not have cancer.

Usually, referring to cancer as “cancer” is a mistake. The word cancer is an umbrella term that encompasses a whole range of diseases that are only really grouped together by a general biological strategy; two cancers are almost always caused by different things, act in different ways, and have different final effects in different parts of the body. The idea of a “cure for cancer” is thus seemingly a pipe dream — but studies like this show that perhaps there are ways to usefully treat all or at least most cancers as a group. That’s of course desirable on the treatment end too, but given how important it is to catch a cancerous mass early in its development, a comprehensive early warning system could be almost as good.

This colorized micrograph shows the difference in shape between white and red blood cells.

The fact that this blood test could easily be made quick and cheap and minimally invasive means it could also help get around many patient behavior problems, like avoiding biopsies, colonoscopies, and prostate exams. If everyone was screened annually with a wide-cast cancer test, a positive result would then lead to a series of possibility-narrowing tests. That’s the sort of logical building that we’re very good at, but there has never been a comprehensive starting point — until now, perhaps.

Bear in mind that the patients in this study only had three different types of cancer, so it is by no means proven that this LGS principle generalizes to all cancers. Also, of course, all of its findings will have to be independently verified before anyone can talk about using it to say a patients should not get further testing.

Assuming that these findings were not outright falsified, though, the big question here seems to be less whether the test can detect cancer than whether it can distinguish cancer from any of a host of other reasons that lymphocytes might experience increased genome sensitivity. This is a very general measurement based on general taxing of the immune system, not anything particularly unique to cancerous cell — it seems to me that false positives will be a real issue. Then again, if something is troubling the body as much as a cancerous tumor, wouldn’t we equally want to know about that? It could very well turn out to be a “major problem” test, which would of course be incalculably useful in its own right.